示例代码：
<!DOCTYPE html><html lang="zh"> ???<head> ???????<meta charset="UTF-8" /> ???????<title>js比较数字相等</title> ???</head> ???<body> ???????<script type="text/javascript"> ???????????//设置误差范围值--机器精度（对于js来说是2^-52） ???????????//ES6定义了Number.EPSILON，之前未定义Number.EPSILON ???????????if(!Number.EPSILON) { ???????????????Number.EPSILON = Math.pow(2, -52) ???????????} ???????????function numberCloseEnoughToEqual(a, b) { ???????????????return(a - b) < Number.EPSILON; ???????????} ???????????console.log(numberCloseEnoughToEqual((0.1 + 0.2), 0.3)); //true ???????</script> ???</body></html>js比较数字相等
原文地址：https://www.cnblogs.com/mengfangui/p/8297187.html